Field of the Invention
This invention relates to a semiconductor device known, for example, from the Proceedings of the 29th Electronic Component Conference (Cherry Hill, NJ, USA; 14 to 16 May 1979), pages 75 to 79.
The above-noted paper, an asymmetrical thyristor having a p.sup.+ n.sup.+ npn.sup.+ structure is described. Between the p.sup.+ layer and the p layer, a thick n layer with a low level of doping and a thin highly doped n.sup.+ layer are provided, the latter acting as a so-called "stop layer". It limits the extent of the space charge zone. In this manner, a p-i-n structure is produced in the component. The edge of the component is chamfered slightly in the positive direction. A second more positive chamfering of the edge is provided in the region of the p layer. These chamferings are intended to prevent a voltage breakdown in the edge region so that higher reverse voltages can be applied to the component. The angles are determined by means of the doping profile. They require careful mechanical edge machining and lead to a relatively large loss of effectively usable area.